[技术]Arizona眼睛模型 [复制链接]

简介 o9v9 bL+X  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 rj5)b:c}  
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模型 ({!*&DVu  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 \}Pr!tk!  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. qEjsAL  
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光源 8}^ym^H|j  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 27H4en; o=  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 P~"""3de4  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Q $>SYvW  
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视网膜的散射 rX&?Xi1JeV  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 h6(L22Hn  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 
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脚本 %w6lNl  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： yAVt[+0  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 6~q"#94  
余下的脚本计算与屈光度有关的所有参数。 CB?H`R pC.  
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分析 p&;,$KDA  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 SkA"MhX  
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脚本代码 R2[!h1nZ  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. rhvsd2z
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Dim entity As T_ENTITY uM~j  
Dim op As T_OPERATION cj/FqU"  
Dim mat As T_MODELMATERIAL K?+Rq  
Dim A As Double :YZMRJL
 
Dim pupilDiam As Double S b3@7^  
Dim eID As Long 6e;.}i  
Dim parID As Long :dzamHbX9  
Dim count As Integer <$ Ar*<,6  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double U=bZy,FT$  
Dim tlens As Double, nlens As Double }' t*BaU  
Dim curv As Double, conic As Double 'H,l\i@"  
Dim ok As Long [VP~~*b  
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Sub Main th*E"@  
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    '用户输入对话框 /P|jHK|{  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 XX(;,[(_  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ,*Yu~4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [(N<E/m%B  
        OKButton 40,91,90,21 etH%E aF[  
        CancelButton 190,91,90,21 r yO\$m  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "L" 6jT  
        TextBox 220,49,40,21,.TextBox2 'default: 4 qcfLA~y  
    End Dialog Io&F0~Z;;(  
    Dim dlg As UserDialog r 6STc,%5  
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    ok = Dialog (dlg) /P0%4aWu=  
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    If ok=0 Then    'cancel button was pressed VscEd
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        Print "Execution cancelled." lH^[b[  
        End qyuU  
    End If y85/qg)H^  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ZWSYh>"  
    If dlg.TextBox1 = "" Then x*[\$E`v  
        A = 0           'Default accommodation g+k0Fw]!  
    Else 70:a2m  
        A = CDbl(dlg.TextBox1) mPxph>o  
    End If FXOA1VEg  
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    If dlg.TextBox2 = "" Then PDo%ob\Ym  
        pupilDiam = 4   'Default pupil diameter :- ydsR/  
    Else \qqt/  
        pupilDiam = CDbl(dlg.TextBox2) $R7n1  
    End If B@l/'$G  
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    Print " " ]`&ws
  
    Print "Accommodation = " & A & " Diopters" yla&/K;|*  
    Print "Pupil Diameter = " & pupilDiam & " mm" Xb=9~7&,$  
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    ' Calculate new parameters with accommodation Llk4=p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness [(Pm\o  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 0t1WvW  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens iP;X8'< BC  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens b$+.}&M  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens QOkPliX  
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    tlens = 3.767 + 0.04*A                  'Lens thickness fNc3&=]]  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction XU .FLNe  
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    'Adjust parameters to account for accommodation B`}?rp  
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    '************************************************************************* %J?;@ G)r  
    'Aqueous thickness (Position of Lens) Im1e/F]  
    '************************************************************************* E[>4b7{g:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1+PLj[;jJ:  
    GetCustomElement eID, entity {SW}S_  
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    parID = FindFullName( "Geometry.Arizona Eye" ) DJ;G0*  
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    ' Delete any shift(s) in z UfSWd
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    count = 0 ^PfFW  
    While GetOperationCount(eID)>count ` a5$VV%J  
        GetOperation eID, count, op ]n0kO&  
        If op.Type="ShiftZ" Then G@anY=D\EB  
            DeleteOperation eID,count !12W(4S5  
            count=count-1 lN)U8  
        End If 69 R
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        count=count+1 Ft>Abj,6  
    Wend NWSBqL5v   
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    'Set new shift in EUU9JnQhBJ  
    op.Type = "ShiftZ" ._"U{ f2V  
    op.val1 = taq TGGeTtk=  
    op.parent = parID V4}9f5FR  
    AddOperation eID, op l njaHol0  
    Print "Set aqueous humor thickness = " & taq-0.55 b;O]@kBB
 
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    '************************************************************************* Zg%U4m:  
    'Radius and conic constant of anterior lens s"<k)Xi  
    '************************************************************************* a%7ju4CVj  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .xuLvNyQr  
    GetConic eID, entity, curv, conic agN`) F!  
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    SetConic eID, entity, 1/Rant, CCant  z@^l1)m  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant b40zYH`'{  
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    '************************************************************************* I2(5]85&]s  
    'Radius and conic constant of posterior lens 4r`u@  
    '************************************************************************* .HF+JHIUu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 6+A<_r`#Q  
    GetConic eID, entity, curv, conic z,[4BM  
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    SetConic eID, entity, 1/Rpost, CCpost J{Ei+@^/9  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost V6?ku6k  
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    '************************************************************************* J5}-5sV^  
    'Lens thickness (Position of posterior lens surface) gYfN?A*`_  
    '************************************************************************* c 's=>-X  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7OYNH0EH  
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    ' Delete any z-shift(s) \1hbCv$Hf  
    count = 0 [ /w{,+U  
    While GetOperationCount(eID)>count ^[Cpu_
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        GetOperation eID, count, op Q5b?- P  
        If op.Type="ShiftZ" Then $&Ng*oX
 
            DeleteOperation eID,count 2?58=i%b  
            count=count-1 LX'.up11X5  
        End If *+re2O)Eh'  
        count=count+1 3:X3n\z  
    Wend uuHR!  
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    'Set new z-shift ehl){Dd^  
    op.Type = "ShiftZ" j{SRE1tqh  
    op.val1 = tlens uA7~`78  
    op.parent = parID RrRrB"!8nR  
    AddOperation eID, op p<*3mbgGO  
    Print "Set lens thickness = " & tlens OACRw%J:X{  
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    '************************************************************************* !*ct3{m  
    'Lens index of refraction "qjkwf)\  
    '************************************************************************* ~UX@%0%)N  
    eID = FindMaterial( "Lens" ) @|v4B[/  
    GetModelMaterial eID, mat I?LJXo\O  
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    mat.Nd = nlens RiqYC3Ka  
    SetModelMaterial eID, mat \:9dt8(-U  
    Print "Set lens index of refraction = " & nlens lfp[(Ph)9  
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    '************************************************************************* O-y/K2MC*  
    'Pupil diameter G?CaCleG  
    '************************************************************************* qk;*$Q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 'd4I/  
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    'Adjust pupil diameter (trimming volume inner hole) q`_d>l  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >UvLeS2h:y  
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    ' Adjust pupil location to just in front of the lens ;= ^kTb`X  
    parID = FindFullName( "Geometry.Arizona Eye" ) jh0``{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) .
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    count = 0 Osncl5PD)  
    While GetOperationCount(eID)>count u+%Ca,6  
        GetOperation eID, count, op xDU>y  
        If op.Type="ShiftZ" Then 'NHtCs=F   
            DeleteOperation eID,count (|+Sbq(o  
            count=count-1 'RK.w^  
        End If 9o5W\.A7[D  
        count=count+1 oU`8\n](  
    Wend X-2rC  
    op.Type = "ShiftZ" dCv@l7hE  
    op.val1 = taq-0.01 qniP
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    op.parent = parID jN 9|q  
    AddOperation eID, op =<Q_&_.60  
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    Print "Set pupil diameter = " & pupilDiam Y|JC+Ee  
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    'Update AZ Eye subassembly Description ]5| o8.  
    eID = FindFullName( "Geometry.Arizona Eye" ) ^f*}]`S  
    GetEntity eID, entity +c;/hM<IX.  
    entity.Description = "Accommodation = " & A & "D" fd~a\5%e  
    SetEntity eID, entity nF$
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    Update YuufgPE*H  
    Print "DONE!" !-%fCg(B  
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End Sub x?s5vxAKf  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 4Ufx,]  
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Accommodation = 4 Diopters |^!#x Tj  
Pupil Diameter = 4 mm EC9D.afy&  
Set aqueous humor thickness = 2.81 >d#oJ?goX  
Set anterior lens radius = 10.4 and conic constant = -2.375869 :lf;CT6$  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 VGFWF3s  
Set lens thickness = 3.927 Gt;@.jY&  
Set lens index of refraction = 1.42672 @;>i3?  
Set pupil diameter = 4 LF o{,%B  
DONE! )D_ZZPq_